Belt-conveyer pulley.



.B. H. MESSITER. BELT coNvEYER PULLEY.. APPLICATION FILED A PB.. 4, 1'910.

Patented Mar. 21, 1911.-

' -BY c 5am NEYs' EDWIN H. MESSITER, 0F BROOKLYN, NEW YORK.

BELT-CONVEYER PULLEY.

Specication of Letters Patent.

Patented Mar. 21, 1911.

Application led April 4, 1910. Serial No. 553,341.

To all whom it may concern:

Be it known that I, EDWIN H. Mnssrrnn, a citizen of the United States of America, and a resident of Brooklyn, county of Kings, and State of New York, have invented certain new and useful Improvements in Belt-Conveyer Pulleys, of which the following is a specification, reference being had to the accompanying d'awings,

forming a part thereof.

My invention relates to improvements in idler pulleys for conveyer belts, and particularly to that class of such idler pulleys comprising a plurality of suspensively supported pulley members connected together by universal joints.

The rotatable elements of universal joints which are pivot-ally connected to rock about axes at right angles to each other, and which intersect at a point coincident with the intersection of the axes of the said elements, do not have synchronous movements of rotation, but, on the contrary, the relative angular velocity thereof alternately increases and decreases, so that the members constantly advance and recede with respect to each other. lVhen such a joint is employed to connect pulley members o'f circular contour, it follows that the surface speeds of the pulley members will constantly vary with respect to each other, but this is undesirable to a high degree for it results in badly wearing both the belt and the joint.

The main object of my present invention is to overcome this defectand to so construct an idler pulley of this description that the surface speeds of its members will notrelatively vary. I attain this object by con structing one or both of a pair of connected pulley elements in form other than of circular contours, the diameter decreasing proportionately to the relative increase of speed at any given point, and increasing as the speed decreases. Idler pulleys of this description comprise two or more elements, usually three or five, but in any set each pair of contiguous elements may be considered as a pair independently of the others, and for convenience of description they will be so considered herein. In such a pair one of the pulley members may have a periphery bounded at any point by a circle and the other a periphery of a varying diameter, or the difference may be divided between them, both having a varying diameter', the

' rotation of the pulley members.

one increasing as the other decreases and vice versa.

My invention also consists in certain novel details of construction and combinations of parts including a novel construction of the pulley members, and a means for adjusting one of the supporting elements for the pulley toward and away from the other to vary the depth of trough formed by the pulley.

To the end that my invention may be fully understood, I will now proceed to describe an embodiment thereof, having reference to the accompanying drawings illustrating the same, and will then point out the novel features in claims.

In the drawings: Figure l is a view in part side elevation and part central longitudinal section of an idler pulley for conveyer belts constructed in accordance with my invention. Fig. 2 is a detail view in central longitudinal section through one of the pulley members. Fig. 3 is an end view of a pulley member having its peripheral contour circular in cross section. Fig. 4; is a transverse sectional view of a pulley member having its peripheral contour oval in cross section.

The idler pulley illustrated comprises three rotatable pulley members l0 connected together by universal joints, and suspensively supported at their ends by end thrust bearings l2 carried by standards 13. The universal joints each comprise knife edge bearing elements 14C-l5 secured respectively to the pulley members to be connected, the said knife edge bearing portions being disposed transversely and in hooked relation with each other, their bearing edges being in substantial engagement at a point coincident with the point of intersection of the axes of The knife edge portions are engaged respectively by bearing surfaces oppositely disposed upon a floating bearing block 16, whereby the said bearing block lmay rock freely with respect to each of the knife edge portions in a direction transverse with respect thereto, but is held against movementin the longitudinal plane thereof. This particular form of universal joint is not claimed herein per se as it forms the subject matter of a separate copending application tiled April 4, 1910, Serial No. 553,342, but it is illustrated as eX- `emplifying a type of universal joint having pivotal movementsin two directions about a 'common point, any form of which results in varying angular velocities of the connected members. The variation of such relative angular velocity is dependent upon the intersecting angle of the axes of rotation of the connected elements, and in general may be said in its limits to be proportional to the sineof such angle and inversely proportionate to the cosine thereof. The variationis, of course, due to thel difference of leverage resulting from the various angles formed between the aXes of the pivots and the axes of rotation of the members, as the joint carrying the pivotal axes rotates. In carrying out my invention I vary the diameter of one or both of the pair ofv connected pulley members to compensate for the varying relative angular velocit-ythus resulting, whereby an equal surface speed of the two members `will result. In Fig. 8 I have shown in end view a pulley whose periphery is represented at any point by a circle, while in Fig.

t I have shown in transverse section a pulley whose diameter is greater in one directionthan in the other. The difference may, of

l course, be divided between the two pulleys if preferred, and I preferably divide the difference in this way so that both pulleys are other than circular, the larger diameter of the one pulley being transversely disposed with respect kto t-he other to Vcorrespond with the transverse dispositionof the two rocking elements of the universal joint. One lreason for preferring to divide this difference between the twoV pulleys is that the irregular movement given to the belt by reason thereof is advantageous in many cases,havingthe f effect of jarring the material carried byv the ing an even and belt toward the center thereof, and maintainproper distribution of the material. As pulleys whose peripheries are notcircular are somewhatdifficult to make, I have devised a special construction therefor as follows: I provide end heads 17 of the proper configuration, and` then draw a tubular shell 18 thereover, the said tubular Vshell being forced to take the shape of the said end heads. Toprovide for the universal joint connection I then take a strip of metal substantially triangular in cross section, and bend it to the form shown in Fig. 2. I insert this in place between the heads and the shell, the heads having cut-away portions to receive the said strip, and I then rivet the strips, Jhead, and shell together. -Prior to finally connecting the parts I loop or hook the bent ends of thestrip of one pulley member over the correspdnding strip of the other pulley member, and finally I mount the bearing blocks 16 in place.

rlhe foregoing constitutes aA simple, inexpensive, strong, and durable form of pulley member and universal joint connection, and

when the holding bolts for the kstandard are freed, the standard being, of course, provided with slotted.y holes to permit of limited movements of adjustment.

What I claim is:

1. The combination of two pulley members arranged end to end, axially at an angle to each other, and connected to rotate at relatively varying angular velocities, the diameters whereof are varied relatively to compensate therefor, whereby the surface speeds thereof will be substantially equal.

2. `The combination of two pulley members arranged end to end, axially at an angle to each other, and connected to rotate at alternatelyincreasing and decreasing relative angular velocities, the peripheral surfaces of the said pulley members having relatively varying radii to compensate therefor, whereby the surface speeds thereof will be substantially equal.

3. Thecombination of two rotatable pulley members disposed end to end, and with their axes at an angle to each other, and a universal joint connecting them, the said pulley members having diameters which are relatively varied to compensate for the varying'angular velocities produced by the y universal joint connections, whereby the surface speeds thereof will be substantially equal.

t. The combination of two rotatable pulley members disposed with their aXes at an angle to each other, the peripheral contour of one of the said pulleys being substantially oval in transverse section, and a universal joint connectingthe said members together.

5. VThe combination of two rotatable pulley members disposed with their axes at an angle to each other, the peripheral contour of the said pulleys being substantially oval in transverse section, one pulley7 member being arranged with its greater diameter substantially in line with the minor diameter of the other said pulley, and a universal joint having two pivotal axes at right angles with respect to each other, connecting them.

6. A conveyer belt idler pulley comprising a plurality of connected members each comprising a tubular shell, and a strap of looped form secured directly to the inner face of the said shell for coengagement with the corresponding strap of another pulley member.

7. A conveyer belt idler pulley comprising a plurality of connected members each comprising a tubular shell, end heads secured thereto, and a strap of looped form, substantially triangular in transverse seei'ion, for Coengagement With the corresponding strap of another pulley member.

8. A oonveyer belt idler pulley comprsing` a plurality of connected members each comprising a tubular shell, and a strap of looped form substantially triangular in 10 transverse section, for coengagement with the corresponding strap of another pulley member.

EDWIN H. MESSITER.

lVtnesses D. HOWARD HAYWooD, LYMAN S. ANDREWS, Jr.

Copies of this patent may be obtained for five oents each, by addressing the Commissioner of Patentst Washington, D. C. 

